Field of the Invention
This invention relates in general to a signal and location device and more specifically to an extremely small, light-weight device for inflating and tethering a lighter-than-air balloon.
In the past many types of signal or rescue balloons have been proposed. These all have the same basic concept of filling a collapsed balloon with lighter-than-air gas from a pressure vessel and tethering the inflated balloon at a signal or rescue position. It has been proposed that these devices would aid in finding lost or injured hunters, hikers, boaters, aviators, and the like.
There are a number of disadvantages to the prior art devices. Although some may be suitable for use in conjunction with a vehicle, they are too large and too heavy to be easily carried by a hiker, skier, or hunter. Additionally, many prior art devices use valving means which are not compatible with the use and storage of helium gas, the principal useable gas. Helium would diffuse thru and leak around these valves; therefore these devices would have short and unreliable useful lifes.
Also, many of the prior art devices send aloft elements other than the balloon and tether line. This extra lifted weight requires a larger balloon and a larger gas vessel which means a larger heavier device.
A spherical balloon as used in prior art devices is not suitable for high wind conditions because the combination of wind drag and tether vectors pushes the balloon toward the ground.
Additionally, it is desirable to use plastic film as balloon material. Plastic film has good helium retention and is durable. Because plastic film does not expand as rubber or other common balloon materials do, plastic film can be coated with a highly reflective coating which greatly aids in sighting of the balloon. However, plastic film is relatively heavy and voluminous so its use in conjunction with the above-mentioned shortcomings of the prior art devices further exacerbates the deficiencies.
Therefore, there has been a need for an extremely small and light-weight rescue/location balloon device which can be carried on the person while hunting, hiking, skiing, or the like. It is particularly desirable that such a device have a long and reliable shelf life. It is further desirable that the device be simple and easy to use. It is particularly desirable that the device utilize a plastic film balloon and that it therefore send aloft minimal weight in addition to the balloon.
It is further desirable that the balloon be a lifting body for use in high wind situations.